Homotopy Perturbation Method for Investigating Population Dynamics in Oxygen‐Depleted Environments

This research will seek to construct a theoretical model to study both the ultraviolet (UV) degradation of hydrogen sulfide (H 2 S) without oxygen and population dynamics in anoxic environments. Solving some of the issues in biogas energy usage, this paper is interested in modeling H 2 S photodegradation, simulation of parameters that influence degradation rate, and testing the model through experimental data. At the same time, the research investigates species survival and extinction under low‐oxygen scenarios, which is very significant for ecological and environmental research. The homotopy perturbation technique is used to construct a detailed model that involves gas flow distribution, radiation kinetics, mass balance, degradation rates, population distribution, survival kinetics, resource availability, and extinction thresholds. It was found that increased retention times resulted in better H 2 S degradation while species with prolonged adaptation time showed enhanced survival under oxygen‐limited conditions. The model prediction agrees closely with experimental and field observations. This integrated methodology offers important insights into maximizing H 2 S photodegradation in biogas systems and population stability under oxygen‐limited conditions.